Switches have been known heretofore that have included features affording opening thereof under contact sticking or welding conditions. For example, positive action switches such as shown in H. W. Hults U.S. Pat. No. 3,035,134, dated May 15, 1962, have been provided with an operating mechanism that positively and unyieldingly transmits force to the movable contacts to provide shear for breaking any weld. E. L. Long copending Application Ser. No. 735,691, filed Oct. 26, 1976, and assigned to the assignee of this application, shows a safety disconnect switch that opens a series connection in the event the switch contacts weld. While these prior switches have been useful for their intended purpose, this invention relates to a safety-disconnect switch that does not rely on forcibly opening welded contacts but instead opens a separate close-first open-last contact that normally does not weld.